Method of testing materials and machine embodying the same



B. GUILLERY.

MHH-0D 0F TESTING MATERIALS AND MACHINE EMBODY'ING THE SAME. AFPucAT'loN. min APR. 2r |920.

, R. GUILLERY. METHOD OF TESTING MATERIALS AND MACHINE EMBODYING THE SAME. APPLICATION FILEDy APR. 2, 1920.

1,375,385. Patented Apr.` 19, 1921.

3 SHEETS-SHEET 2- IIIIIIIIIIIIIIII lIlI IIIIIIIIIIIIIIIIIII mamey H. GUILLERY. METHOD OF TESTING MATERIALS AND MACHINE EMBODYING THE SAME.

APPLICATION FILED APR.2. 1920. 1,37 5,385.

3 SHEETS-SHEET 3.

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J'/ c d a J n f a IIIII a img Patented Apr. 19, 192L ory the UNiiE RENE GUILLEEY, 0EV rAEis, EEANcE.Y

Application filed April 2, 1920. Serial No. 370,864.

To all whom t may concern Be it known that I, REN GUILLERY, re-

siding at Paris, (Seine Department,) No. 111 yue de Flandre, citizen of the French Republic, have invented Ycertain. new and useful Improvements in Methods of Testing Materials and Machine Emb'odying the c Same, which are fully set forth in vthe following specification.

This invention relates to a method of testing materials which allows of determining in a precise manner the termination of the period in which the deformations are proportional to the loads, and at the same time the modulus of elasticity of the material under test.

The invention isessentially characterized by the fact that the loadl representing the limit of proportionality between the deformation of a metal and the loads acting thereon, is determined by theobservation of the compensation required in order to annui the variations of--a certain volume of water which 'is subjected to an increase representing a function of the value of the elongation sag, and to a diminution which is a function of the value of the load. Y

The useof 'the limit of' proportionality e l which is obtained in an exact manner, to-

gether with the-modulus of elasticity m, will 2 afford, a means for obtaining the value ef/] which characterizes the elastic resilience,

' e., the value which multiplied by a fracenergy tion of the volume of a metal (this being a fraction which varies according to the conditions of the stress) will give the amount of which this metal can absorb without being subjected Vto a permanent deformation.

The accompanying drawingsrepresent by way of example a practical embodiment of Figure 1 is a plan view of the achine used for bending tests'.

Fig.A 2isa vertical section alongl the line p-g passing through the axis of the pistonemployed for the bendingV tests.

Fig. 3 is a vertical section along the line r-s passing through the axis of movement of the pressure balance system.

Fig. 4 is a vertical section along the line t-u passing through the axis of the handoperated piston and the supply tank.

Fig. 5 is a vertical section along the line :Vc-Jy passing through the axis of the piston used for bending tests. Y

Fig. 6 is a view in elevation representing the system employed forv transmission of elongationsjin a traction testing machine.

Specification of Letters Patent.v Patented Apr.Y 19, 19121.

Fig. 7 is a plan view of the same transmission system. l

Fig. 8 is a diagram representing the curve of a traction test.

Fig. 9 representsthe drawing method for n 2 determining the value of when e kand m are known. Y

As disposed fo-r bending'tests, the device V comprises two pistons A and B adapted to receivepressure which is exerted either by hand yor by the'use of an independent hydraulic pressure. Where hand pressure is used, the apparatus contains the pistonfC Vwhich is operatedzeither by hand or by direct ressure, or again (after blocking the nut by means of a device with partial or cut-away screw-thread, upon the main body of the cylinder E) by screwing the piston into its nut D when thus blocked inthe fixed position. .This operating piston receives its liquid from a supply tank F which is fedV by infiltration from the cylinders of the pistons A,Band C.

The piston A pushes against the test bar orlspecimen Gr which rests upon two supports H, these latter vbeing represented in the present example as .mounted upon the main frame of the machine. Y

The piston A which is used for bending purposes is caused to rest, vthrough the intermediary of aV pointed stud, Fig. 2 upon a circular diaphragm I, by the use of the `frame J connectedi to the piston A. 'This diaphragm I is constituted by a metal disk attachedtofa sheet rubber disk, this latter being held in tight position at the outer part of a member If which forms a water chamiber, the rubber disk having a .somewhat larger diameter than the-.metal disk forming part of the diaphragm I. On the other hand, the saidmember K carries a second diaphragm L of the same kind as the foregoing, which constitutes a chamber in communication with the chamber of the diaphragm I and which is adjustable-by means of the thumb screw M. The common'reservoir thus constituted is also in communica-V tion with a glass tube N provided with a standard gage mark O.

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The piston B pushes against a swinging phragm I, and the water chamber thus composed is caused to communicate through a `flexible tube V with the fixed member K and consequently with the tube N.

Therod of the diaphragm U bears upon the flat upper surface of the lever P, and when the sliding carriage T is displaced by means of the screw Xpa second portion screw-threaded in the 'contrary sense is caused to operate the sliding carriage 7/ which effects the displacement of the counterweight a for the purpose of counterbalancing the pressure of the diaphragm U upon the lever P. The graduated scale on the guiding way of the sliding carriage T r will. indlcatethe scale number represent-v ing the modulus of elasticity,

i Y note is taken ofthe water level in the tube depending on the displacement of the said carriage.

Moreover, the pressure gage W connected with the pressure system will afford a means for determining the limiting load e.

The present device as `adapted for bending tests operates in the following man-- ner.. Y

With the test bar or specimen disposed in the proper position and the diaphragm chambersbeing filled with water, lthe piston c is operated in order to produce a certain `pressure'whlch is transmitted to the pistons L and B, and to the pressure gage W; due

N, this level having been previously brought to the standard mark 0 by means of the screw M. Should this lever rise or fall, the

screw X is turned in the proper direction to reduce the displacementofthe level, and

this action is-repeated as often as-required.

`When the level inallyremains in a fixed position, this will show that the scale of loads corresponds to the scale of values of i the sag or dip of the specimen, and the stationary position ofthe level indicates that the elfect is proportionalA The testing is continued by increasing'the loadup to the moment `where the level becomes displaced, `and this indicates that the conditions of proportionality have now ceased to prevail. The gage W shows the limit load e, while the position of the sliding carriage T indicates the value of the modulus m.

Figs. 6 and 7 represent the manner in which the diaphragm I can be replaced by the diaphragm g which transmits to the liquid contained the glass tube N the elongations or the sag'of ythe test bar or specimen which are transmitted to this diaphragm by thesaid test bar, the remainder of the apparatus remaining the same, it being understood .that the motive pressure can be produced upon thepiston B at the same y time as upon the tractive piston, instead of being'produced by hand operation on the piston' G 1 Y The method of operating is similar for the two tests in question. r

It is desirable that the relative dimensions of the members of the apparatus should be so designedthat the displacements ofthe diaphragme acting in contrary senseV on the water level of the tube should be in exact correspondence during the period of proportionality. F or instance, in traction testing, it is required that the coefficient of elongartions crand the coeiiicient V of the loads constituting the series, shall be of such value that during the period of proportionality, the condition KzV shall always prevaihi. e., that the straight part ofthe traction curve shall be situated' at 4:5 degrees as represented in the diagram Fig. 8. When thevalues of the limit e and the modulusm have been determined according to the tests,'it will be an 2 easy matter to find the value AInFig.

9 is shown the method by which a graduated -rule and a square can beemployed for obtaining this value in a rapid manner.u q It is evident that various modifications can'be made in this machine, and that theV arrangement or the form of the members thereof can be Vvaried `without departing lfrom the principle of the invention.`

Having now described my invention, what I claim as new and desireto secure by Letters'- 1. A method for testing material consisting in applying varying force to a test specimen ofthe material by means Yof fluid under pressure, causing such pressure to produce a proportional change in the volume of liquid in a container, causing the yield ofthe specimen to e'ect a `proportional change in the volume of said container, then determining the limiting load for proportionality by observation of, the amount of compensation required to annul the variations ofi the volume of liquid in said container subjected to an increase-which is a function 'of the amount of elongation or of sag of the'test specimen, and to diminution which is a function of the value of the load. l

change in the volume of said container, then determining the limiting load for proportionality by observation of the amount of compensation required to annul the variations of the volume of the liquid in said container subjected to an increase Which is a function of the amount of the elongation or of sag of the test specimen and to a diminution Which is a function of the value of the load, and adjusting the level of the liquid so as to measure the coeflicient of elasticity of the material.

3. A method of testing materials con-z sisting in applying varying force to a test specimen of the material by means of fluid under pressure, simultaneously causing such pressure to produce a proportional change in the volume of liquid in a container, causing the yield of the specimen to eEect a proportional change in the volume of said container, then determining the limiting load for proportionality by observation of the amount of compensation required to annul the variations of the volume of liquid in said container subjected to an increase Which is a function of the amount of elongation or of sag of the test specimen, and to a diminution Which is a function ofthe value of the load, and indicating the nal pressure applied to said specimen.

4. An apparatus for testing materials comprising a pressure operated member adapted to bear against the specimen of material to be tested, a closed chamber having a plurality of movable diaphragms and a liquid volume indicating device, said member engaging one of said diaphragms and designed to permit movement of the same as the specimen yields under the pressure applied to said member, a second pressure operated member operatively connected With the second diaphragm and designed to move the same to decrease the volume of said chamber, means for applying equal pressure to said members and means for indicating the amount of pressure applied to said members.

In testimony whereof I have signed my name to this specification.

REN GUILLERY. 

